It is conventional to treat effluent water from a septic tank (which has already undergone an anaerobic fermentation reaction, and removal of solids, in the septic tank) by passing the water through a tile-bed, or other means for aerating the water. The resulting aerobic reaction is micro-biological, and requires a residence time generally of such length that the tile bed or other means has to be physically large (and therefore expensive).
In CA-2,096,175, the effluent water is passed over a heap of blocks of soft resilient foam material. The blocks are so heaped that air can circulate freely between and around the blocks. The foam is of the open-cell, or interconnected-cell, type, in which the water soaks into the interior of the blocks as well as being present on the outside surfaces of the blocks. As a result, a mix of aerobic and anaerobic conditions obtains in the blocks, and the reactions that take place reflect these conditions. This leads to a very efficient utilisation of the space envelope of the heap of blocks, in terms of the volumetric flow rate that can be treated in the heap, and also allows the heap to continue to function for long periods without a build-up of sludge.
The present invention may be regarded as a development of the technology shown in CA-2,096,175 in that the invention is aimed at providing a manner of containing the heap of blocks of foam material, for convenience of transport, and efficacy of operation. As will be explained, the invention may also be applied for the containment of other forms of treatment media.